What do the following two equations represent? $4x+4y = -3$ $-20x-20y = 15$
Solution: Putting the first equation in $y = mx + b$ form gives: $4x+4y = -3$ $4y = -4x-3$ $y = -1x - \dfrac{3}{4}$ Putting the second equation in $y = mx + b$ form gives: $-20x-20y = 15$ $-20y = 20x+15$ $y = -1x - \dfrac{3}{4}$ The above equations turn into the same equation, so they represent equal lines.